JP5544895B2 - Fluorine gas generator - Google Patents

Description

  The present invention relates to a fluorine gas generator.

  As a conventional fluorine gas generation apparatus, an apparatus that uses an electrolytic cell and generates fluorine gas by electrolysis is known.

  Patent Document 1 includes an electrolytic bath 32 for electrolyzing hydrogen fluoride in an electrolytic bath made of a molten salt containing hydrogen fluoride, and a product gas containing fluorine gas as a main component in the first gas phase portion on the anode side. A fluorine gas generation device that generates a by-product gas mainly containing hydrogen gas in a second gas phase portion on the cathode side is disclosed.

  The electrolytic cell 32 is provided with a raw material pipe 82 for supplying hydrogen fluoride as a raw material into the molten salt. A hydrogen fluoride source 84 and a nitrogen source 94 are connected to the raw material pipe 82 via pipes 83 and 93. A switching valve 86 is disposed on the pipe 83 on the hydrogen fluoride source 84 side, and a switching valve 96 is disposed on the pipe 93 on the nitrogen source 94 side.

JP 2004-43885 A

  In the fluorine generating apparatus as described in Patent Document 1, when the entire apparatus is brought to an emergency stop due to a trouble such as a power failure, the switching valves 86 and 96 are automatically closed to supply hydrogen fluoride and nitrogen gas. Blocked. At this time, the hydrogen fluoride vapor remaining in the raw material pipe 82 dissolves in the molten salt of the electrolytic cell 32, and the pressure in the raw material pipe 82 decreases, so that the molten salt in the electrolytic cell 32 flows back to the raw material pipe 82. Can happen. In that case, the molten salt that has flowed back solidifies and closes the raw material pipe 82.

  As described above, when the entire apparatus is stopped due to a trouble such as a power failure, it cannot be stopped safely. In addition, when restarting, it is necessary to restore the blocked raw material piping, and therefore it is not possible to restart immediately.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a fluorine gas generation device that can be safely stopped at an emergency stop and can be restarted quickly.

  The present invention relates to a fluorine gas generating device that generates fluorine gas by electrolyzing hydrogen fluoride in a molten salt, the fluorine generated at an anode in which the molten salt is stored and immersed in the molten salt. The first gas chamber in which main gas mainly composed of gas is guided and the second chamber in which by-product gas mainly composed of hydrogen gas generated at the cathode immersed in the molten salt is guided are melted. An electrolytic cell separated on the surface of the salt solution, and hydrogen fluoride gas vaporized from the molten salt of the electrolytic cell and mixed in the main gas generated from the anode is solidified using a refrigerant. A purifier for collecting and purifying fluorine gas, a hydrogen fluoride supply passage for replenishing the electrolytic cell with hydrogen fluoride of a hydrogen fluoride supply source, and hydrogen fluoride of the hydrogen fluoride supply source Supply entrained gas to the electrolytic cell to the hydrogen fluoride supply passage The emergency stop facility, and an emergency stop facility that operates when the fluorine gas generator is in an emergency stop. The solidification of hydrogen fluoride gas in the purifier instead of the entrained gas that is shut off when the entrained gas shut-off valve is closed due to the loss of the drive source due to the emergency stop of the fluorine gas generator An alternative gas supply facility capable of supplying the refrigerant used for the replacement gas as an alternative gas, an alternative gas cutoff valve for switching supply and cutoff of the alternative gas of the alternative gas supply facility to the hydrogen fluoride supply passage, and the fluorine An instrument gas supply facility for emergency stop that has an instrument gas shut-off valve that can be opened to supply instrument gas when the drive source is lost due to an emergency stop of the gas generator. At the time of emergency stop of the raw gas generator, the substitute gas shut-off valve is opened upon receipt of the instrument gas supply from the instrument gas supply equipment for emergency stop, and the substitute gas of the substitute gas supply equipment is the hydrogen fluoride. It supplies to a supply channel | path, It is characterized by the above-mentioned.

  According to the present invention, at the time of an emergency stop, the instrumentation gas shut-off valve is opened due to the loss of the operating source, so that the substitute gas shut-off valve is opened upon receipt of the supply of the instrumentation gas. Since the alternative gas is supplied to the hydrogen fluoride supply passage, the molten salt is prevented from flowing back into the hydrogen fluoride supply passage. Therefore, in an emergency of the fluorine gas generation device, the fluorine gas generation device can be safely stopped, and the fluorine gas generation device can be restarted promptly.

1 is a system diagram showing a fluorine gas generation device according to an embodiment of the present invention. It is a systematic diagram showing an instrument gas supply facility for emergency stop.

  Embodiments of the present invention will be described below with reference to the drawings.

  With reference to FIG. 1, the fluorine gas production | generation apparatus 100 which concerns on embodiment of this invention is demonstrated.

  The fluorine gas generation device 100 generates fluorine gas by electrolysis and supplies the generated fluorine gas to the external device 4. The external device 4 is, for example, a semiconductor manufacturing device. In this case, fluorine gas is used as a cleaning gas, for example, in a semiconductor manufacturing process.

  The fluorine gas generation device 100 includes an electrolytic cell 1 that generates fluorine gas by electrolysis, a fluorine gas supply system 2 that supplies the fluorine gas generated from the electrolytic cell 1 to the external device 4, and the generation of fluorine gas. And a by-product gas processing system 3 for processing the generated by-product gas.

  First, the electrolytic cell 1 will be described.

  The electrolytic bath 1 stores a molten salt containing hydrogen fluoride (HF). In the present embodiment, a mixture (KF · 2HF) of hydrogen fluoride and potassium fluoride (KF) is used as the molten salt.

The inside of the electrolytic cell 1 is partitioned into an anode chamber 11 and a cathode chamber 12 by a partition wall 6 immersed in the molten salt. In the molten salt of the anode chamber 11 and the cathode chamber 12, the anode 7 and the cathode 8 are immersed, respectively. By supplying a current from the power source 9 between the anode 7 and the cathode 8, a main gas mainly composed of fluorine gas (F ₂ ) is generated at the anode 7, and hydrogen gas (H ₂ ) is generated at the cathode 8. By-product gas as a main component is generated. A carbon electrode is used for the anode 7, and soft iron, monel, or nickel is used for the cathode 8.

  On the surface of the molten salt solution in the electrolytic cell 1, a first gas chamber 11a into which fluorine gas generated at the anode 7 is guided, and a second gas chamber 12a into which hydrogen gas generated at the cathode 8 is guided. Are partitioned by the partition wall 6 so that the mutual gas cannot pass. As described above, the first air chamber 11a and the second air chamber 12a are completely separated by the partition wall 6 in order to prevent a reaction due to the contact of fluorine gas and hydrogen gas. On the other hand, the molten salt in the anode chamber 11 and the cathode chamber 12 is not separated by the partition wall 6 but communicates through the lower portion of the partition wall 6.

  Since the melting point of KF · 2HF is 71.7 ° C., the temperature of the molten salt is adjusted to 90 to 100 ° C. In each of the fluorine gas and the hydrogen gas generated from the anode 7 and the cathode 8 of the electrolytic cell 1, hydrogen fluoride is vaporized from the molten salt by the vapor pressure and mixed. As described above, each of the fluorine gas generated at the anode 7 and guided to the first air chamber 11a and the hydrogen gas generated at the cathode 8 and guided to the second air chamber 12a includes hydrogen fluoride gas. Yes.

  The electrolytic cell 1 is provided with a liquid level gauge 13 as a liquid level detector for detecting the liquid level of the stored molten salt. Nitrogen gas is supplied to the liquid level gauge 13 as a purge gas from a nitrogen gas supply source 45 through a purge gas supply passage 44. Nitrogen gas supplied to the level gauge 13 is purged into the molten salt at a constant flow rate through the insertion tube 13 a inserted in the electrolytic cell 1. The liquid level gauge 13 is a back pressure type liquid level gauge that detects the back pressure when nitrogen gas is purged into the molten salt and detects the liquid level from the back pressure and the liquid specific gravity of the molten salt. The purge gas supply passage 44 is provided with a shutoff valve 43 that switches between supply and shutoff of nitrogen gas.

  The shut-off valve 43 is an air drive valve that is driven by compressed air supplied from a compressor (not shown), and is a normally closed valve that closes when no compressed air is supplied.

  Next, the fluorine gas supply system 2 will be described.

  A first main passage 15 for supplying fluorine gas to the external device 4 is connected to the first air chamber 11a.

  The first main passage 15 is provided with a first pump 17 for deriving and transporting fluorine gas from the first air chamber 11a. As the first pump 17, a positive displacement pump such as a bellows pump or a diaphragm pump is used.

  A purification device 16 is provided upstream of the first pump 17 in the first main passage 15 to collect the hydrogen fluoride gas mixed in the main raw gas and purify the fluorine gas. The refining device 16 is a device that separates and removes hydrogen fluoride gas from fluorine gas by utilizing the difference in boiling point between fluorine and hydrogen fluoride.

  The purifier 16 has an inner tube 61 as a gas inflow portion into which fluorine gas containing hydrogen fluoride gas flows, and hydrogen fluoride gas mixed in the fluorine gas solidifies while the fluorine gas passes through the inner tube 61. And a cooling device 70 for cooling the inner tube 61 at a temperature not lower than the boiling point of fluorine and not higher than the melting point of hydrogen fluoride.

  The inner tube 61 is a bottomed cylindrical member, and the upper opening is sealed with a lid member 62. The lid member 62 is connected to an inlet passage 63 that guides the fluorine gas generated in the anode 7 into the inner tube 61 and an outlet passage 65 that discharges the fluorine gas from the inner tube 61. The inlet passage 63 and the outlet passage 65 constitute a part of the first main passage 15.

  The inlet passage 63 is provided with an inlet valve 64 that allows or blocks the inflow of fluorine gas to the inner tube 61. The outlet passage 65 is provided with an outlet valve 66 that allows or blocks the outflow of fluorine gas from the inner tube 61.

  The cooling device 70 can partially accommodate the inner tube 61 and can store liquid nitrogen as a refrigerant therein, and a liquid nitrogen supply / discharge system 72 that supplies and discharges liquid nitrogen to and from the jacket tube 71. With.

  The jacket tube 71 is connected to a liquid nitrogen supply passage 77 that guides the liquid nitrogen supplied from the liquid nitrogen supply source 76 into the jacket tube 71. The liquid nitrogen supply passage 77 is provided with a flow rate control valve 78 for controlling the supply flow rate of liquid nitrogen. A pressure gauge 80 that detects the internal pressure of the jacket tube 71 is provided downstream of the flow rate control valve 78 in the liquid nitrogen supply passage 77.

  The inside of the jacket tube 71 consists of two layers of liquid nitrogen and vaporized nitrogen gas, and the liquid level of liquid nitrogen is detected by a liquid level gauge 74.

  The jacket tube 71 is connected to a nitrogen gas discharge passage 79 for discharging the nitrogen gas in the jacket tube 71. The nitrogen gas discharge passage 79 is provided with a pressure adjustment valve 81 that controls the internal pressure of the jacket tube 71. The pressure adjustment valve 81 controls the internal pressure of the jacket tube 71 to be a predetermined pressure based on the detection result of the pressure gauge 80. This predetermined pressure is determined so that the temperature of the liquid nitrogen in the jacket tube 71 is not lower than the boiling point of fluorine (−188 ° C.) and not higher than the melting point of hydrogen fluoride (−84 ° C.). Specifically, the pressure is set to 0.4 MPa so that the temperature of the liquid nitrogen in the jacket tube 71 is about −180 ° C. Thus, the pressure regulating valve 81 controls the internal pressure of the jacket tube 71 to 0.4 MPa so that the temperature of liquid nitrogen in the jacket tube 71 is maintained at about −180 ° C. Nitrogen gas discharged through the pressure regulating valve 81 is released to the atmosphere.

  As the liquid nitrogen in the jacket tube 71 is vaporized and discharged, the liquid nitrogen in the jacket tube 71 decreases. Therefore, the flow control valve 78 is supplied from the liquid nitrogen supply source 76 to the jacket tube 71 so that the liquid level of the liquid nitrogen in the jacket tube 71 is kept constant based on the detection result of the liquid level gauge 74. Control the supply flow rate of liquid nitrogen.

  Since the inner tube 61 is cooled by the jacket tube 71 to a temperature not lower than the boiling point of fluorine and not higher than the melting point of hydrogen fluoride, only hydrogen fluoride mixed in the fluorine gas is solidified in the inner tube 61, and the fluorine gas is Pass through the inner tube 61. In this way, hydrogen fluoride gas mixed in the main gas is collected and the fluorine gas is purified.

  A first buffer tank 21 for storing the fluorine gas transported by the first pump 17 is provided downstream of the first pump 17 in the first main passage 15. The fluorine gas stored in the first buffer tank 21 is supplied to the external device 4.

  A flow meter 26 that detects the flow rate of the fluorine gas supplied to the external device 4 is provided downstream of the first buffer tank 21. The power source 9 controls the current value supplied between the anode 7 and the cathode 8 based on the detection result of the flow meter 26. Specifically, the amount of fluorine gas generated in the anode 7 is controlled so that the amount of fluorine gas supplied from the first buffer tank 21 to the external device 4 is replenished to the first buffer tank 21.

  In this way, the amount of fluorine gas generated at the anode 7 is controlled so as to supplement the amount of fluorine gas supplied to the external device 4, so that the internal pressure of the first buffer tank 21 is higher than atmospheric pressure. Maintained. On the other hand, since the external device 4 side where fluorine gas is used is atmospheric pressure, if the valve provided in the external device 4 is opened, the pressure difference between the first buffer tank 21 and the external device 4 As a result, the fluorine gas is supplied from the first buffer tank 21 to the external device 4.

  On the upstream and downstream sides of the first buffer tank 21 in the first main passage 15, cutoff valves 22 and 23 that permit or block the flow of fluorine gas are provided.

  The inlet valve 64, the outlet valve 66, the shut-off valve 22, and the shut-off valve 23 provided in the first main passage 15 are air-driven valves that are driven by compressed air supplied from the compressor, and when no compressed air is supplied. Is a normally closed valve that closes.

  Next, the byproduct gas processing system 3 will be described.

  A second main passage 30 for discharging hydrogen gas to the outside is connected to the second air chamber 12a.

  The second main passage 30 is provided with a second pump 31 for deriving and transporting hydrogen gas from the second air chamber 12a.

  Nitrogen gas is supplied upstream of the second pump 31 in the second main passage 30 from the nitrogen gas supply source 45 through the dilution gas supply passage 32 as a dilution gas for preventing explosion that reduces the concentration of hydrogen gas. The dilution gas supply passage 32 is provided with a shutoff valve 33 that switches between supply and shutoff of nitrogen gas.

  A shutoff valve 35 that switches between the flow and shutoff of hydrogen gas is provided upstream of the second pump 31 in the second main passage 30.

  An abatement part 34 is provided downstream of the second pump 31 in the second main passage 30, and the hydrogen gas transported by the second pump 31 is rendered harmless by the abatement part 34 and released.

  The shut-off valve 33 provided in the dilution gas supply passage 32 and the shut-off valve 35 provided in the second main passage 30 are air-driven valves that are driven by compressed air supplied from the compressor. When no compressed air is supplied, It is a normally closed valve that closes.

  The fluorine gas generation device 100 also includes a raw material supply system 5 that supplies hydrogen fluoride, which is a raw material of fluorine gas, into the molten salt of the electrolytic cell 1. Below, the raw material supply system 5 is demonstrated.

  The electrolytic cell 1 is connected to a hydrogen fluoride supply source 40 in which hydrogen fluoride for replenishing the electrolytic cell 1 is stored through a hydrogen fluoride supply passage 41. Hydrogen fluoride stored in the hydrogen fluoride supply source 40 is supplied into the molten salt of the electrolytic cell 1 through the hydrogen fluoride supply passage 41. The hydrogen fluoride supply passage 41 is provided with a shutoff valve 42 for switching between supply and shutoff of hydrogen fluoride from the hydrogen fluoride supply source 40 to the electrolytic cell 1.

  Further, nitrogen gas is supplied to the hydrogen fluoride supply passage 41 from the nitrogen gas supply source 45 as the accompanying gas supply source through the accompanying gas supply passage 46. The accompanying gas supply passage 46 is provided with a shutoff valve 47 as an accompanying gas shutoff valve for switching between supply and shutoff of the accompanying gas. The accompanying gas is a gas for introducing hydrogen fluoride into the molten salt of the electrolytic cell 1. Nitrogen gas, which is an accompanying gas, is hardly dissolved in the molten salt and is discharged from the second air chamber 12a through the byproduct gas processing system 3.

  The shut-off valve 42 provided in the hydrogen fluoride supply passage 41 and the shut-off valve 47 provided in the accompanying gas supply passage 46 are air-driven valves that are driven by compressed air supplied from the compressor, and when no compressed air is supplied. Is a normally closed valve that closes.

  As described above, the level gauge 13 of the electrolytic cell 1 is provided with the shut-off valve 43 that is a normally closed type air-driven valve.

  Further, the fluorine gas supply system 2 is provided with an inlet valve 64, an outlet valve 66, a cutoff valve 22, and a cutoff valve 23 that are normally closed air-driven valves.

  Further, the byproduct gas processing system 3 is provided with a shut-off valve 33 and a shut-off valve 35 which are normally closed type air-driven valves.

  Further, the raw material supply system 5 is provided with a shut-off valve 42 and a shut-off valve 47 which are normally closed type air-driven valves.

  During an emergency stop of the fluorine gas generation device 100 due to a power failure or a compressor failure, these air-driven valves are closed due to loss of compressed air as a drive source.

  In that case, since the supply of the nitrogen gas that is the purge gas is shut off in the liquid level gauge 13, the hydrogen fluoride vapor in the electrolytic cell 1 flows into the liquid level gauge 13, and the liquid level gauge 13 is There is a risk of corrosion and failure.

  Further, in the fluorine gas supply system 2, since the inner tube 61 and the first pump 17 of the purifier 16 are sealed, the internal pressure of the inner tube 61 and the first pump rises, and there is a possibility that the fluorine gas leaks. .

  In addition, in the byproduct gas processing system 3, since the supply of the nitrogen gas that is the dilution gas is interrupted, the concentration of the hydrogen gas in the second main passage 30 may increase.

  In the raw material supply system 5, the supply of hydrogen fluoride from the hydrogen fluoride supply source 40 to the electrolytic cell 1 and the supply of nitrogen gas, which is an accompanying gas, are shut off. As a result, the hydrogen fluoride vapor remaining in the hydrogen fluoride supply passage 41 is dissolved in the molten salt in the electrolytic cell 1 and the pressure in the hydrogen fluoride supply passage 41 is reduced, so that the molten salt in the electrolytic cell 1 is fluorinated. There is a risk of flowing back into the hydrogen supply passage 41. In that case, there is a possibility that the hydrogen fluoride supply passage 41 may be blocked due to solidification of the backflowed molten salt.

  Furthermore, since the inside of the electrolytic cell 1 is hermetically sealed, the internal pressure may increase and the molten salt may leak.

  As these countermeasures, the fluorine gas generation device 100 is equipped with an emergency stop facility that operates during an emergency stop and safely stops the entire device. Below, an emergency stop facility is demonstrated.

  The emergency stop facility replaces the nitrogen gas of the nitrogen gas supply source 45 which is shut off by closing each air drive valve with the loss of the drive source due to the emergency stop of the fluorine gas generation device 100, and substitutes the substitute gas. An alternative gas supply facility 201 that can be supplied, and an instrument gas supply facility 210 for emergency stop that can supply instrument gas to the alternative gas supply facility 201 when the drive source is lost due to an emergency stop of the fluorine gas generator 100 (See FIG. 2).

  The alternative gas supply facility 201 collects and stores the liquid nitrogen discharged and used for the solidification of the hydrogen fluoride gas in the cooling device 70 of the purification device 16, and can supply nitrogen gas as an alternative gas. A tank 202 is provided.

  A liquid nitrogen discharge passage 90 for discharging liquid nitrogen is connected to the jacket tube 71 of the cooling device 70. The downstream end of the liquid nitrogen discharge passage 90 is connected to the nitrogen buffer tank 202. The liquid nitrogen discharge passage 90 is provided with a refrigerant cutoff valve 203 that switches between discharging and blocking liquid nitrogen in the jacket tube 71 to the nitrogen buffer tank 202. The refrigerant shut-off valve 203 is an air-driven valve that is driven by instrument gas supplied from the emergency stop instrument gas supply facility 210, and is a normally closed valve that is closed in a normal state where no instrument gas is supplied. It is.

  Since the nitrogen buffer tank 202 is disposed below the jacket tube 71, the liquid nitrogen in the jacket tube 71 is discharged to the nitrogen buffer tank 202 by gravity when the refrigerant shut-off valve 203 is opened.

  The inside of the nitrogen buffer tank 202 that has received the discharge of liquid nitrogen consists of two layers of liquid nitrogen and nitrogen gas. Connected to the nitrogen buffer tank 202 is an alternative gas supply passage 204 for supplying the internal nitrogen gas as an alternative gas to various parts of the fluorine gas generator 100. The alternative gas supply passage 204 is provided with an alternative gas cutoff source valve 205 that switches between supply and cutoff of the alternative gas. Further, a pressure reducing valve 206 for reducing the alternative gas to a predetermined pressure is provided downstream of the alternative gas cutoff source valve 205.

  The alternative gas supply passage 204 is formed to be branched into a plurality of parts in the middle, and the nitrogen gas in the nitrogen buffer tank 202 is supplied to various portions of the fluorine gas generation device 100 as an alternative gas of the nitrogen gas of the nitrogen gas supply source 45. Specifically, the alternative gas supply passage 204 includes an alternative purge gas supply passage 204a that supplies a purge gas to the level gauge 13, an alternative dilution gas supply passage 204b that supplies a dilution gas to the second main passage 30, and hydrogen fluoride. It is branched to an alternative accompanying gas supply passage 204c for supplying accompanying gas to the supply passage 41.

  The alternative purge gas supply passage 204a is provided with an alternative purge gas cutoff valve 207 that switches between supply and cutoff of the purge gas, and the alternative dilution gas supply passage 204b is provided with an alternative dilution gas cutoff valve 208 that switches between supply and cutoff of the dilution gas. The alternative accompanying gas supply passage 204c is provided with an alternative accompanying gas cutoff valve 209 for switching between supply and cutoff of the accompanying gas.

  The alternative gas cutoff source valve 205, the alternative purge gas cutoff valve 207, the alternative dilution gas cutoff valve 208, and the alternative accompanying gas cutoff valve 209 are air-driven driven by instrumentation gas supplied from the emergency stop instrumentation gas supply facility 210. It is a normally closed valve that is a valve and is closed in a normal state where no instrument gas is supplied.

  Further, the insertion pipe 13a of the liquid level gauge 13 is formed by branching in parallel in the middle, and one of the passages is provided with a normal supply valve 242 that is in an open state during normal operation and enables supply of purge gas. The other passage is provided with an emergency supply valve 243 that is open when the fluorine gas generation device 100 is in an emergency stop and enables supply of purge gas.

  The normal supply valve 242 is an air-driven valve that is driven by compressed air supplied from a compressor (not shown), and is a normally closed valve that closes when no compressed air is supplied. The emergency supply valve 243 is an air-driven valve that is driven by instrument gas supplied from the emergency stop instrument gas supply equipment 210, and is normally closed that is closed in a normal state where no instrument gas is supplied. It is a type valve.

  As shown in FIG. 2, the instrument gas supply facility 210 for emergency stop includes a cylinder 211 as an instrument gas container filled with compressed air that is an instrument gas. In the cylinder 211, instrumentation for supplying the internal instrumentation gas to the refrigerant shutoff valve 203, the alternative gas cutoff source valve 205, the alternative purge gas cutoff valve 207, the alternative dilution gas cutoff valve 208, and the alternative accompanying gas cutoff valve 209. A gas supply passage 212 is connected. The instrumentation gas supply passage 212 is provided with an instrumentation gas cutoff valve 213 that switches between supply and cutoff of the instrumentation gas. Further, a pressure reducing valve 214 for reducing the instrument gas to a predetermined pressure is provided downstream of the instrument gas cutoff valve 213. The instrumentation gas cutoff valve 213 is an air-driven valve that is driven by compressed air supplied from a compressor, and is a normally open valve that opens when no compressed air is supplied. Therefore, in the normal state where the compressor is in operation, the instrumentation gas shut-off valve 213 is closed.

  The instrumentation gas shut-off valve 213 opens due to the loss of compressed air, which is a drive source, when the fluorine gas generation device 100 is in an emergency stop due to a power failure or a compressor failure. As a result, the instrumentation gas in the cylinder 211 passes through the instrumentation gas supply passage 212, the refrigerant cutoff valve 203, the alternative gas cutoff source valve 205, the alternative purge gas cutoff valve 207, the alternative dilution gas cutoff valve 208, the alternative accompanying gas cutoff valve 209, The valves 203, 205, 207, 208, 209, and 243 that are supplied to the emergency supply valve 243 and supplied with instrumentation gas as a drive source are opened. Thus, at the time of an emergency stop of the fluorine gas generation device 100, the refrigerant cutoff valve 203, the alternative gas cutoff source valve 205, the alternative purge gas cutoff valve 207, the alternative dilution gas cutoff valve 208, the alternative accompanying gas cutoff valve 209, and the emergency supply The valve 243 is opened.

  A release passage 215 for releasing the instrumentation gas to the atmosphere is branched and provided downstream of the pressure reducing valve 214 in the instrumentation gas supply passage 212. The discharge passage 215 is provided with an orifice 216 serving as a flow rate limiting unit that limits the discharge flow rate of the instrument gas. Thus, after the instrumentation gas shut-off valve 213 is opened, the instrumentation gas in the instrumentation gas supply passage 212 is released to the atmosphere through the discharge passage 215. When the pressure of the instrument gas falls below the required driving pressure of each valve 203, 205, 207, 208, 209, 243 as the instrument gas in the instrument gas supply passage 212 is released into the atmosphere, each valve 203, 205, 207, 208, 209 and 243 are closed. The total amount of instrument gas is determined by the capacity of the cylinder 211, and the discharge flow rate of the instrument gas is determined by the diameter of the orifice 216. Therefore, the opening time of the refrigerant shut-off valve 203, the alternative gas cutoff source valve 205, the alternative purge gas cutoff valve 207, the alternative dilution gas cutoff valve 208, the alternative accompanying gas cutoff valve 209, and the emergency supply valve 243 is the capacity of the cylinder 211. And the diameter of the orifice 216 is adjusted.

  Instead of configuring the instrumentation gas shut-off valve 213 with an air-driven valve, it may be configured with a normally open solenoid valve that uses electricity as a drive source and opens when no electricity is supplied. Good. Even in this configuration, the instrument gas cutoff valve 213 is opened due to the loss of the drive source when the fluorine gas generation device 100 is stopped due to a power failure, so the refrigerant cutoff valve 203, the alternative gas cutoff source valve 205, The alternative purge gas cutoff valve 207, the alternative dilution gas cutoff valve 208, the alternative accompanying gas cutoff valve 209, and the emergency supply valve 243 are opened.

  Next, emergency stop equipment in the fluorine gas supply system 2 and the byproduct gas processing system 3 will be described with reference to FIG.

  The emergency stop facility includes an abatement path 221 provided in parallel with the first main path 15.

  The upstream side of the inlet valve 64 in the first main passage 15, that is, the first air chamber 11 a of the electrolytic cell 1 and the abatement passage 221 are connected through the first discharge passage 222. Between the inlet valve 64 and the outlet valve 66 in the first main passage 15, that is, the inner tube 61 of the purification device 16 and the removal passage 221 are connected through the second discharge passage 223. Further, a bypass passage 225 that bypasses the first pump 17 is connected between the outlet valve 66 and the shutoff valve 22 in the first main passage 15, and the bypass passage 225 and the removal passage 221 are connected to the third discharge passage 224. Connected through.

  A detoxifying section 226 is provided in the detoxifying passage 221, and the fluorine gas discharged through the discharge paths 222, 223, and 224 is rendered harmless by the detoxifying section 226 and released.

  The discharge passages 222, 223, and 224 are provided with shut-off valves 227, 228, and 229 that switch between discharging and shutting off fluorine gas from the first main passage 15 to the removal passage 221. Further, check valves 230, 231, and 232 that allow only the flow of fluorine gas from the first main passage 15 to the removal passage 221 are provided downstream of the shutoff valves 227, 228, and 229.

  The shut-off valves 227, 228, and 229 are air-driven valves that are driven by instrument gas supplied from the emergency stop instrument gas supply facility 210, and are normally closed when the instrument gas is not supplied. It is a type valve. Therefore, the shut-off valves 227, 228, and 229 are opened upon receiving the supply of instrumentation gas as a drive source when the fluorine gas generation device 100 is in an emergency stop.

  A bypass passage 240 that bypasses the shut-off valve 35 is connected to the second main passage 30. A bypass cutoff valve 241 is provided in the bypass passage 240.

  The bypass shut-off valve 241 is an air-driven valve that is driven by instrument gas supplied from the emergency stop instrument gas supply facility 210, and is a normally closed valve that is closed in a normal state where no instrument gas is supplied. It is. Therefore, the bypass shut-off valve 241 opens upon receiving the supply of instrumentation gas as a drive source when the fluorine gas generation device 100 is in an emergency stop.

  Next, the operation of the emergency stop facility will be described.

  At the time of emergency stop of the fluorine gas generator 100 due to a power failure or compressor failure, the supply of compressed air from the compressor to the shut-off valves 43, 47, 33 is stopped. The supply of nitrogen gas to the hydrogen fluoride supply passage 41 and the second main passage 30 is shut off. In addition, since the supply of compressed air from the compressor to the inlet valve 64, the outlet valve 66, the shutoff valve 22, the shutoff valve 23, and the shutoff valve 35 of the byproduct gas processing system 3 in the fluorine gas supply system 2 is also stopped, Each valve is also closed. Therefore, during the emergency stop of the fluorine gas generation device 100, the situation described above may occur at various points of the fluorine gas generation device 100.

  However, the instrumentation gas shut-off valve 213 is opened due to loss of compressed air as a driving source, and the refrigerant shut-off valve 203, the substitute gas shut-off valve 205, the substitute purge gas shut-off valve 207, the substitute dilution gas shut-off valve 208, and the alternative accompanying The gas shut-off valve 209 opens upon receiving the instrument gas supplied from the cylinder 211.

  By opening the refrigerant shut-off valve 203, the liquid nitrogen in the jacket tube 71 is discharged to the nitrogen buffer tank 202. The nitrogen buffer tank 202 that has received the liquid nitrogen is composed of two layers of liquid nitrogen and nitrogen gas. The nitrogen gas passes through the alternative purge gas supply passage 204a, the alternative dilution gas supply passage 204b, and the alternative accompanying gas supply passage 204c. It is supplied to the liquid level gauge 13, the second main passage 30, and the hydrogen fluoride supply passage 41. In the liquid level gauge 13, the emergency supply valve 243 is also opened by receiving the instrument gas supplied from the cylinder 211, so that the normal supply valve 242 closed by the stop of the supply of compressed air from the compressor is bypassed. A purge gas is then fed into the molten salt. Thus, even if the supply of the nitrogen gas from the nitrogen gas supply source 45 is shut off, the nitrogen gas is supplied as an alternative gas from the nitrogen buffer tank 202, so the same state as before the emergency stop of the fluorine gas generation device 100 is achieved. Can keep. Therefore, the failure of the liquid level gauge 13, the increase of the hydrogen gas concentration in the second main passage 30, and the blockage of the hydrogen fluoride supply passage 41 due to the reverse flow of the molten salt are prevented.

  By opening the instrumentation gas shutoff valve 213, the shutoff valves 227, 228, and 229 of the fluorine gas supply system 2 are also opened upon receipt of the instrumentation gas supplied from the cylinder 211. As a result, the first air chamber 11 a, the inner tube 61, and the first pump 17 of the electrolytic cell 1 communicate with the abatement passage 221. Further, by opening the instrumentation gas cutoff valve 213, the bypass cutoff valve 241 of the byproduct gas processing system 3 is also opened by receiving the supply of instrumentation gas from the cylinder 211. Thereby, the 2nd air chamber 12a of the electrolytic cell 1 is connected to the abatement part 34, and the same state as before the emergency stop of the fluorine gas production | generation apparatus 100 is maintained. As described above, even when the valves of the fluorine gas supply system 2 and the byproduct gas processing system 3 are closed at the time of emergency stop of the fluorine gas generator 100, the electrolytic cell 1, the inner tube 61, and the first pump 17 are sealed. The state is prevented and the internal pressure is prevented from rising.

  Since the instrumentation gas supplied from the cylinder 211 is released to the atmosphere through the discharge passage 215, after a predetermined time has elapsed, each valve that has been opened by the supply of the instrumentation gas is closed. Here, in the liquid level gauge 13, since both the normal supply valve 242 and the emergency supply valve 243 are closed, the electrolytic gas is electrolyzed even after the supply of the purge gas is stopped by closing the alternative purge gas cutoff valve 207. The hydrogen fluoride vapor in the tank 1 is prevented from flowing into the liquid level gauge 13. In addition, since the emergency supply valve 243 is closed after the insertion pipe 13a is sufficiently replaced with the purge gas, the liquid level gauge 13 promptly adjusts the liquid level of the molten salt when the fluorine gas generator 100 is restarted. Can be detected.

  The capacity of the cylinder 211 defining the valve opening time of each valve and the diameter of the orifice 216 are the required supply flow rate of the alternative gas to the liquid level gauge 13, the hydrogen fluoride supply passage 41, and the second main passage 30, and the electrolytic cell. 1 and from the viewpoint of preventing pressure rise of the inner tube 61 and the first pump 17.

  As described above, even when the fluorine gas generation device 100 is urgently stopped, due to the operation of the emergency stop facility, the hydrogen fluoride supply passage 41 is blocked, the liquid level gauge 13 is broken, the electrolytic cell 1 and the first main passage 15 are An increase in pressure, an increase in the concentration of hydrogen gas in the second main passage 30 and the like are prevented, and the fluorine gas generation device 100 can be safely stopped. Therefore, when a power failure, a compressor failure, or the like is recovered, the fluorine gas generator 100 can be restarted quickly without performing a special operation such as gas replacement of the hydrogen fluoride supply passage 41.

  According to the above embodiment, there exist the effects shown below.

  At the time of an emergency stop of the fluorine gas generator 100, the instrumentation gas shut-off valve 213 is opened, and accordingly, the liquid nitrogen in the jacket tube 71 serves as a substitute gas for the liquid level gauge 13, the hydrogen fluoride supply passage 41, and the second main While being supplied to the passage 30, an increase in pressure in the electrolytic cell 1 and the first main passage 15 is prevented. Therefore, the fluorine gas generation device 100 can be safely stopped in an emergency of the fluorine gas generation device 100, and when the power failure or the compressor failure is recovered, the fluorine gas generation device 100 can be restarted promptly. Can do.

  Below, the other form of the said embodiment is demonstrated.

  (1) In the above embodiment, compressed air filled in the cylinder 211 is used as instrumentation gas. Instead, the nitrogen gas in the nitrogen buffer tank 202 may be used as an instrumentation gas. That is, the nitrogen gas in the nitrogen buffer tank 202 may be used as an alternative gas for the nitrogen gas of the nitrogen gas supply source 45 and also as an instrument gas for the emergency stop instrument gas supply equipment 210. However, it is desirable to supply the instrumentation gas from the cylinder 211 from the viewpoint of ensuring the supply amount of nitrogen gas and the required driving pressure of each valve that opens upon receiving the instrumentation gas.

  (2) In the above embodiment, after recovering the liquid nitrogen discharged from the cooling device 70 of the purification device 16 in the nitrogen buffer tank 202, the nitrogen gas in the nitrogen buffer tank 202 is used as an alternative gas. . Instead, the liquid nitrogen discharged from the cooling device 70 may be directly used as an alternative gas. In that case, it is necessary to gasify the liquid nitrogen by providing a vaporizer utilizing heat exchange on the downstream side of the liquid nitrogen discharge passage 90.

  (3) In the above embodiment, liquid nitrogen is used as the refrigerant used in the purification device 16. However, the refrigerant is not limited to liquid nitrogen, and liquid argon or the like may be used.

  (4) In the above embodiment, power failure or compressor failure was cited as the cause of the emergency stop of the fluorine gas generator 100. However, the cause of the emergency stop of the fluorine gas generation device 100 is not limited to this, and the failure of the control device of the fluorine gas generation device 100 and the manual and automatic emergency stop due to the failure of the electrolytic cell 1 and each valve are also possible. Including.

  (5) In the above embodiment, the nitrogen buffer tank 202 is disposed below the jacket tube 71. However, the nitrogen buffer tank 202 may be arranged at the same level as the jacket tube 71 or above the jacket tube 71. In that case, in order to discharge the liquid nitrogen in the jacket tube 71 to the nitrogen buffer tank 202, it is necessary to provide a pump driven by the instrumentation gas in the cylinder 211 in the liquid nitrogen discharge passage 90. Further, instead of providing a pump, the liquid nitrogen in the jacket tube 71 may be discharged to the nitrogen buffer tank 202 by pressurizing the gas phase portion in the jacket tube 71.

  (6) In the above embodiment, as the shutoff valve of the alternative gas supply facility 201, in addition to the substitute gas shutoff source valve 205, the substitute purge gas shutoff valve 207, the substitute dilution gas shutoff valve 208, and the substitute accompanying gas shutoff valve 209 are also provided. It comprised so that it might provide. However, instead of this, only the alternative gas cutoff source valve 205 is provided or only the alternative purge gas cutoff valve 207, the alternative dilution gas cutoff valve 208, and the alternative accompanying gas cutoff valve 209 are provided without the alternative gas cutoff source valve 205. You may comprise so that it may provide.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The present invention can be applied to an apparatus that generates fluorine gas.

DESCRIPTION OF SYMBOLS 100 Fluorine gas production | generation apparatus 1 Electrolysis tank 2 Fluorine gas supply system 3 By-product gas processing system 4 External device 5 Raw material supply system 7 Anode 8 Cathode 13 Liquid level meter 15 1st main channel | path 16 Purifier 17 1st pumps 22 and 23 Shut off Valve 30 Second main passage 32 Dilution gas supply passages 33, 35 Shutoff valve 40 Hydrogen fluoride supply source 41 Hydrogen fluoride supply passages 42, 43 Shutoff valve 44 Purge gas supply passage 45 Nitrogen gas supply source 46 Accompanying gas supply passage 47 Shutoff valve 61 Inner tube 64 Inlet valve 66 Outlet valve 71 Jacket tube 90 Liquid nitrogen discharge passage 201 Alternative gas supply equipment 202 Nitrogen buffer tank 203 Refrigerant cutoff valve 204 Alternative gas supply passage 205 Alternative gas cutoff source valve 207 Alternative purge gas cutoff valve 208 Alternative dilution gas Shut-off valve 209 Alternative accompanying gas shut-off valve 210 Emergency stop instrumentation Gas supply equipment 211 Cylinder 213 Instrument gas shut-off valve 215 Release passage 216 Orifice 221 Detoxification passage 227, 228, 229 Shut-off valve 230, 231, 232 Check valve 241 Bypass shut-off valve

Claims (5)

A fluorine gas generator that generates fluorine gas by electrolyzing hydrogen fluoride in a molten salt,
A first air chamber in which a main gas mainly composed of fluorine gas generated in an anode immersed in the molten salt is introduced and hydrogen generated in the cathode immersed in the molten salt. An electrolytic cell in which a second gas chamber into which a by-product gas containing a gas as a main component is guided is separated on the surface of the molten salt solution;
A purifier for purifying fluorine gas by solidifying and collecting hydrogen fluoride gas vaporized from the molten salt in the electrolytic cell and mixed with the main raw gas generated from the anode using a refrigerant;
A hydrogen fluoride supply passage for replenishing the electrolytic cell with hydrogen fluoride of a hydrogen fluoride supply source;
An accompanying gas supply source for supplying an accompanying gas for introducing hydrogen fluoride of the hydrogen fluoride supply source to the electrolytic cell to the hydrogen fluoride supply passage;
An accompanying gas cutoff valve for switching between supply and cutoff of the accompanying gas of the accompanying gas supply source;
An emergency stop facility that operates during an emergency stop of the fluorine gas generator, and
The emergency stop facility is:
Instead of the entrained gas shut off when the entrained gas shut-off valve is closed due to the loss of the drive source due to the emergency stop of the fluorine gas generating device, the purifying apparatus is for solidifying hydrogen fluoride gas. An alternative gas supply facility capable of supplying the refrigerant used in
An alternative gas cutoff valve that switches between supply and cutoff of the alternative gas supply facility to the hydrogen fluoride supply passage;
An instrument gas supply facility for emergency stop having an instrument gas shut-off valve that opens to accompany the loss of the drive source accompanying an emergency stop of the fluorine gas generation device and can supply instrument gas;
At the time of an emergency stop of the fluorine gas generator, the substitute gas shut-off valve is opened upon receipt of the instrument gas supplied from the instrument gas supply equipment for emergency stop, and the substitute gas of the substitute gas supply equipment is the fluoride gas. A fluorine generator, which is supplied to a hydrogen supply passage. The purification apparatus is
A gas inflow part into which a main gas containing hydrogen fluoride gas flows,
While the hydrogen fluoride gas mixed in the main gas is solidified, the gas inflow part is used as a refrigerant at a temperature not lower than the boiling point of fluorine and not higher than the melting point of hydrogen fluoride so that the fluorine gas passes through the gas inflow part. A cooling device for cooling
The alternative gas supply facility is:
A buffer tank capable of collecting and storing the refrigerant discharged from the cooling device and supplying the refrigerant as an alternative gas;
A refrigerant shut-off valve that switches between discharging and shutting off the refrigerant of the cooling device to the buffer tank,
During an emergency stop of the fluorine gas generator, the refrigerant shut-off valve is opened upon receipt of the instrument gas supply from the instrument gas supply facility for emergency stop, and the refrigerant in the cooling device is discharged to the buffer tank. The fluorine gas generation device according to claim 1, wherein: The instrument gas supply equipment for emergency stop is
An instrument gas container filled with instrument gas;
A discharge passage that is provided downstream of the instrument gas shut-off valve and discharges instrument gas to the atmosphere;
The fluorine gas generation device according to claim 1, further comprising: a flow rate limiting unit that is provided in the discharge passage and limits a discharge flow rate of the instrument gas.   The refrigerant stored in the buffer tank is used as an alternative gas for the accompanying gas, and also as an instrument gas for the instrument gas supply facility for emergency stop. The fluorine gas production | generation apparatus of description. A first main passage connected to the first air chamber for supplying the main component gas to an external device;
The emergency stop facility is:
A passage for detoxification provided in parallel with the first main passage;
A discharge passage connecting the first main passage and the abatement passage;
A shut-off valve that is provided in the discharge passage and switches between discharging and shutting off the main gas from the first main passage to the abatement passage;
At the time of emergency stop of the fluorine gas generator, the shutoff valve is opened upon receipt of instrument gas supply from the instrument gas supply facility for emergency stop, and the main gas in the first main passage is used for the detoxification. The fluorine gas generator according to any one of claims 1 to 4, wherein the fluorine gas generator is discharged into a passage.

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